Spa alkalinity regulators

• Use strips or a liquid kit (more accurate).
  
• Frequency: 1×/week, and always after a long swim or adding product.
  
  

• Targets: pH 7.2–7.8 · Total alkalinity 100–150 ppm · Calcium hardness 100–200 ppm
  
• Order: Alkalinity → pH → Hardness. Adjust only one parameter at a time. Wait 20-30 minutes between each product.

First, stabilize total alkalinity at 100–150 ppm. Proper alkalinity buffers pH and limits roller coasters. Then, fine-tune pH.

• pH stability: alkalinity “buffers” the pH. Too low = pH roller coaster; too high = pH difficult to lower.
  
• Problem prevention: Correct alkalinity limits corrosion, turbidity and scaling.

To adjust the alkalinity of a spa, you must first measure the current level using a test kit or test strips. If the alkalinity is too low, add an alkalinity booster; if it is too high, use an Alka Minus product. The goal is to achieve a value between 100 and 150 ppm, which stabilizes the pH and improves the effectiveness of chlorine or bromine. Proper alkalinity makes the water more comfortable, reduces pH fluctuations, and protects spa components from corrosion and scale buildup.

• Then aerate (jets/bubbles) to raise the pH without raising the total alkalinity too much.
  
• Re-test and repeat in stages.
  
• Symptoms of total alkalinity outside the range:
  
• Too low (<100 ppm) → unstable pH, “aggressive” water, risk of corrosion, irritations.
  
• Too high (>150 ppm) → pH difficult to lower, cloudy water, limescale deposits.
  
• Tip: Adjust only one product at a time, follow the label, and respect the balancing order: total alkalinity → pH → hardness.

Total alkalinity is the buffering capacity of water: it stabilizes pH and prevents sudden changes. The target in spas is 100–150 ppm. Below this, pH becomes unstable and the water can become aggressive to surfaces and metals; above this, pH becomes difficult to lower and cloudiness/scale may appear.

To increase the alkalinity of a spa, you need to use a product designed to raise it, often called “Alka+”, “alkalinity booster”, or “alkalinity plus”. Add the product directly to the spa water, according to the recommended dosage based on the spa's volume. The ideal alkalinity is between 0 and 150 ppm and acts as a buffer to stabilize the pH. When the alkalinity is too low, the pH becomes unstable and fluctuates constantly. After adding the product, circulate the water for 20 to 30 minutes, then retest to confirm the reading.

To lower excessively high alkalinity in a spa, use an "Alka-minus" product or an alkalinity reducer. Add a small amount of the product near a jet, with the pump running, and let the water circulate for 20 to 30 minutes before testing again. Excessive alkalinity can raise the pH, make the water cloudy, and reduce the effectiveness of sanitizers like chlorine and bromine. Always correct alkalinity gradually to avoid lowering the pH too much.